Felicity Huffman has nothing to prove in her portrayal of a man becoming a woman in "Transamerica." Even to San Francisco, home to an estimated 6,000 transsexuals. The quality of her acting, she says, "is for the transgender community to decide."

Huffman, 43, was nominated for two best-actress Golden Globes on Dec. 14 -- as Stanley/Bree in "Transamerica" and as the beleaguered mom Lynette in "Desperate Housewives," the series that has dominated America's water-cooler conversations since it premiered last year. A victory in either category would make a nice bookend with the Emmy Huffman won for "Housewives" this year.

In a phone interview from her car in Los Angeles, Huffman discusses the road to her most un-desperate situation: the dizzying night of winning the Emmy, the thank-yous from embattled housewives, the $250,000-an-episode salary that all the earnest indies in the world could never match. While she had a blip of recognition as a hard-nosed producer on the late-'90s sitcom "Sports Night" and in a guest stint on "Frasier" in 2003, "Desperate Housewives" and now "Transamerica" have changed everything.

The confluence of the two parts seemed almost cosmic. On the day she had her first reading for "Desperate Housewives," Huffman got the call from "Transamerica" writer-director Duncan Tucker that she'd gotten the part. Five days after the movie wrapped, Huffman was on the set to shoot the first season of "Housewives."

For anyone on the cusp of a breakthrough in series TV, "Transamerica" could be considered a gamble. Never stooping to caricature, Huffman plays Bree as an uptight, overeducated middle-aged matron -- who just happens to have an extra body part. Before the hormone-flooded Bree has surgery, she drives across the country in a soul-baring journey with a teenage son she never knew she had.

"I'm not a beauty. That's not my thing. So it wasn't like I was risking anything," says Huffman, whose small frame and angular face have won her more than a few brainy roles. "What I was risking is whether I could do it. There are many places to fall."

To help get into character, Huffman enlisted "Andy," a prosthetic penis she bought at a New York sex shop and stuffed into her girdle to do a urinating scene in the film. She interviewed transsexuals to nail the nuances, but she says the toughest work came in presenting Bree's emotional transformation. Bree disguises herself as a church missionary when she plucks her son from a life of street hustling in New York.

"Bree's change takes place not when she has her sexual reassignment but when her heart breaks open," Huffman says.

Filming in New York allowed Huffman around-the-clock absorption while her husband, Oscar-nominated actor William H. Macy ("Fargo"), took care of their 3- and 5-year-old daughters. Macy came on board as executive producer after the film wrapped to give it "juice," Huffman says. He corralled Harvey Weinstein into a screening at the Tribeca Film Festival, and Weinstein bought the distribution rights for his new company.

In barnstorming the festival circuit (including the San Francisco International Lesbian and Gay Film Festival), she says she sensed that her instinct-over-method approach connected.

"There have been usually one or two transgender people (at each festival) who stop me afterward and talk about the movie and say that it meant a lot to them and they're really glad a woman played the role," she says. "If it couldn't be a transgender woman, they're really glad it was a woman."

While sex changes have not become a dramatic thread weaving through the weekly travails on Wisteria Lane, some critics have complained that "Desperate Housewives" has weakened in its second season. Huffman counters that, this being the United States, everybody is entitled to an opinion.

"They were waiting for us to fight before we even started airing," she says. "I mean, it was last year before we even got on the air, and we were reading rags, and I'd say, 'Look, Nicollette. I'm in a fight with you.' "

Her inner unemployed actress keeps Huffman from getting too giddy about prime-time supremacy, even if producers are already interviewing directors for the series' next season. And, like Lynette, juggling kids and work doesn't leave her the time.

"I'm completely at sea and drowning and unprepared all of the time," she says. "I haven't figured it out at all."

"Transamerica" (R) opened this weekend in Bay Area theaters. Ron Dicker is a freelance writer.